**Low beam headlights** or **dipped headlights** are mainly used at night on all types of roads and during the day in specific situations such as tunnels or temporary lanes. These lights are essential when there is a risk of dazzling other drivers or when driving at less than 40 km/h.

On the other hand, **high beam headlights** or **main beam headlights** are used on roads outside urban areas, especially at night or in poorly lit tunnels. They are mandatory when driving at more than 40 km/h in these conditions. However, they should not be used within towns or cities, nor when the vehicle is stationary.

Both types of lights can be used simultaneously in situations where the aforementioned restrictions are not violated. For example, on roads outside urban areas and without the risk of dazzling others, it is possible to combine both lights to improve visibility. Therefore, the correct answer is **yes**, they can be used simultaneously.